EPTMy rough idea (WIP):
I propose a new special ability called "Smoke Screen Rounds" to be given to either Siege Tanks, which would make most sense, or to Warhounds for balance purposes. In real live warfare, smoke screens are used to hide troop movement, in advance or retreat. Usually such smoke screens would be generated by artillery batteries that fire smoke rounds ahead of advancing armies to help them cover open ground that has little or no cover, helping them close in on the enemy.
This Smoke Screen ability, if given to the Siege Tanks, would be a cooldown ability, otherwise Siege Tanks would have energy bars. Each tank would have 1 round that would generate a cloud of thick smoke in a radius, perhaps as large as a psi storm or blinding cloud. Keep in mind that the tank can fire this anywhere within the range of its regular artillery weapon.
The properties of the Smoke Screen are that like that of a reversed blinding cloud/dark swarm. Units would not be able to shoot into or out of the Smoke Screen and it would kind of work like the fog of war in a way. Only units within the Smoke Screen may shoot at one another: for example, the only way to kill enemy marines in SS is to run your own marines in there. Scans, obs, and overseers would not reveal units within SS (lore explanation: Smoke Screen Rounds deploy smoke that have Jamming abilities) to units OUTSIDE the SS but would reveal them to units inside the SS so that units like cloaked ghosts can still be killed.
Keep in mind this is a pretty rough idea. Maybe it is good, maybe it is crap. I'd like to hear some feedback or some more input to further develop this.
TL:DR
Terran Dark Swarm
-works like fog of war
-no shooting into or out of, but can shoot within
-spells like storm/fungal/emp still work against it
-units inside can't be revealed by detection (scan, obs) to the outside, but can inside
Interesting Uses/Facts
-Realistic Ability for Terran Race
-Makes Widow Mines useful in stopping armies advancing in Smoke Screen
-Helps Terran break siege lines in TvT by allowing armies to maneuver into sieged Tanks
